Seven years. That is how long the Southeastern Conference has dominated college football, a streak led by Alabama, which has won three of the last four BCS titles.

How long will this onslaught last?

That depends on two things—the identify of the head coach and the NCAA.

College football is cyclical. But winning programs that incurred a coaching change or NCAA sanctions—sometimes both—saw their dynasties end.

Alabama, Nebraska and Oklahoma were three of the most dominant teams in the 1970s. They won a combined seven national titles.

Alabama head coach Bear Bryant won six national titles before retiring in 1982. Alabama won another title in 1992 under Gene Stallings but would then go on a 17-year drought. The school faced three major NCAA investigations from 1995 to 2009 and was slapped with postseason bans and vacated victories.

Oklahoma faced the wrath of the NCAA in 1988. Head coach Barry Switzer left the program in 1989 because of notorious scandals that occurred during his watch. The NCAA sanctioned the Sooners with postseason and television bans and scholarship reductions.

Nebraska coach Tom Osborne (1973-97) never coached a team that finished with less than nine wins in one season. His teams won two national titles in 1994-95 and shared a title with Michigan in 1997. Since Osborne retired, five Nebraska teams have finished the season unranked by the AP and only three finished in the AP's final Top 10.

Tom Osborne's Nebraska Cornhuskers

The Miami Hurricanes stormed through the 80s as one of the more fearsome teams in the country. They won three national titles in that decade. Nobody could stop the Hurricanes...except for the NCAA. Miami was rocked by scandals including the infamous Pell Grant scandal. In 1995 the NCAA hammered Miami with a postseason ban and stripped its scholarships for the next three years.

USC won two championships in 2003-04 but its 2004 BCS Championship was vacated due to NCAA sanctions. In addition to vacated victories, USC was placed on a two-year postseason ban and stripped of 30 scholarships over three years. USC head coach Pete Carroll left for the Seattle Seahawks at the end of the 2009 season. Since Carroll's departure, USC's record is 32-19.

USC 55 vs Oklahoma 19

Florida won two BCS titles in 2006 and 2008 but it hasn't played in a BCS Championship since then-head coach Urban Meyer left in 2010.

LSU won its first BCS title under then-head coach Nick Saban in 2003. Saban left for the NFL's Miami Dolphins on Christmas day 2004. Head coach Les Miles won the school's second BCS title in 2007 but he did that with Saban's senior class—he has not won a BCS title with his own players.

If it is not a coaching change that affects a team's momentum, it is the NCAA's imposing heavy hand. The more a coach wins, the more every school or NFL team wants him. He heads the short list of every athletic director or NFL general manager.

Winning also has another downside. The more a team wins, the more high profile it becomes. More eyes are watching, including those in Indianapolis where the NCAA is headquartered.

Brian Spurlock-USA TODAY Sports

NCAA headquarters

So far, Alabama is the team to beat in the foreseeable future. Alabama is no longer on NCAA probation but it still is within that five-year repeat offender window.

If the Tide stay clean and Nick Saban continues to coach at Tuscaloosa, Alabama should keep rolling.

Saban will be 62 years old this October. He's already dabbled in the NFL. Unless the most powerful man in sports is offered an absurd amount of money to coach somewhere else, he's staying put.

The only way we can predict how long Alabama will continue to dominate is to predict how long Saban will be at Alabama. It's that easy.

We're predicting Saban retires after having won his seventh title at Alabama. Saban currently has four BCS titles but one of those belongs to LSU. To catch Bryant, he needs three more. To be Alabama's all-time leader, he needs four.

Bear Bryant interview

We're giving him five years to win four, just like an NCAA student-athlete scholarship.

Piece of cake.

Note—National champions were determined by using the criteria of an AP, UPI, USAT or BCS title.